1. Field of Invention
Described herein are techniques that can improve the performance of semiconductor devices (e.g., transistors and diodes) formed of wide bandgap semiconductor materials. Such devices may be used in applications such as power electronics, power amplification and digital electronics, by way of example.
2. Discussion of the Related Art
Improved power transistors are desired for advanced transportation systems, more robust energy delivery networks and new approaches to high-efficiency electricity generation and conversion. Such systems rely on very efficient converters to step-up or step-down electric voltages, and use power transistors capable of blocking large voltages. In hybrid vehicles, for example, power transistors with blocking voltages of more than 500 V are used to convert DC power from the batteries to AC power to operate the electric motor.
Conventional power devices (e.g., transistors or diodes) used in such applications are made of silicon. However, the limited critical electric field of silicon and its relatively high resistance causes available commercial devices, circuits and systems to be very large and heavy, and operate at low frequencies. Therefore, such commercial devices are unsuitable for future generations of hybrid vehicles and other applications.
Nitride semiconductor devices have been proposed as offering the potential for producing high-efficiency power electronics demanding high blocking voltages and low on-resistances.